1. Field of the Invention
The present invention relates to a new and improved piercing die assembly for punching a plurality of radially extending holes in a tubular member in a one shot operation whereby the die assembly can pierce as many as one hundred (100) or more holes, or slots, in round and square tubing, cups or metal boxes.
2. Description of the Prior Art
Heretofore, horn dies or indexing dies have been used to punch articles of various types.
Examples of such prior art devices are found in the following U.S. Patents:
______________________________________ U.S. PAT. NO. PATENTEE ______________________________________ 1,398,320 Dunsworth 1,503,551 Nice 1,581,810 Patrick 2,315,340 Knudsen 2,326,536 Hartsock 2,329,020 Wales 2,419,534 Burleson 2,423,791 Nelson 2,630,862 Musser 2,875,829 Patrick 3,374,697 Robinson 3,485,124 Merchant 3,557,649 Kirchner 3,579,767 Reider 3,580,122 Powell 3,756,108 Fuchs, Jr. 3,782,231 Jannetty 3,949,632 Kappan 4,269,094 Long, et al ______________________________________
In the Dunsworth Pat. No. 1,398,320 the basic idea and differences are as follows: This device pierces one configuration or part at a time at a given location, then the machine indexes the part itself to again pierce the same configuration. The moving parts and the action of this machine are totally different for the head reciprocates up and down and is activated by gear driven mechanisms. The location of the configuration is again controlled by the use of gears which means after prolonged use the location may differ from original.
In the Nice U.S. Pat. No. 1,503,551 the basic differences from our construction are as follows: The side pierce action of this machine pushes down on the part which in turn pushes the pad down. The levers 22 are pivoted on rods 21 in the stationary blocks of the machine. Thus, a basic difference exists in this machine whereby an activating lever must be provided for every hole that is to be pierced in the piece part or band. Another problem with a machine of this type is that where the band is of a thicker material, the size of the lever and its pivot must be enlarged for punching which limits the number of holes you can punch into a given sized band.
In Patrick U.S. Pat. No. 1,581,810 the basic idea and differences are as follows: The flywheel which is labeled "s" in the drawing (FIG. 2) is activated by a motor which turns the crank shaft that is connected to a knee. The knee itself is guided below the table. The toggle joint is connected to the knee which is labeled "j" in FIG. 2. When the crank shaft is at the resting or neutral position, the toggle brings the slide back away from the part (FIG. 4). The action is controlled from the bottom and only two punches can be punched at any given time.
In Knudson U.S. Pat. No. 2,315,340, the basic idea and differences are as follows: This device uses the basic slide cam principle to pierce holes. The part and whole assembly are activated by the ram pushing down so that the fixed cylindrical stud "20" in FIG. 1 slides the perf assembly over. The main problem with illustrated construction is that when you have two holes in line perpendicular to the base, it is impossible to punch them at the same time without rotating the part. The patented assembly is limited for it can only produce a limited quantity of holes at limited locations and hence the die assembly has a limited hole producing or punching capacity.
In Hartsock et al U.S. Pat. No. 2,326,536, the basic idea and differences are as follows: This device uses four hydraulic cylinders to pierce four equally spaced holes at one time. This machine is capable of indexing the part but each cylinder is in a fixed location. One of the main differences between this machine and our invention is that the prior art machine can only produce a limited number of holes for the indexing device can only be set for a certain number of degrees.
In the Wales U.S. Pat. No. 2,329,020, the basic idea and differences are as follows: This device uses the slide action principle but provides the user with an advantage of moving any of the units around because of the unique one piece construction of the punch and the die. The same device may be used for a number of different parts. This device is limited to the height of the part and to the thickness of the material.
In the Burleson U.S. Pat. No. 2,419,534, the basic idea and differences are as follows: This device uses a single rack and gear which is connected to an inner ring which has rollers fixed in different locations relative thereto. These rollers are used to activate the punches when the rack and gear move the inner ring. The basic difference is that the punches are activated consecutively by pistons and gears moving around the circumference of the rings and not all at one time. There also is no provision for the formation of holes or slots at differing vertical positions of the piece part being punched.
In the Nelson U.S. Pat. No. 2,423,791, the basic idea and differences are as follows: This device uses both of the conventional forms of side piercing. The first part of the device uses the activation of an outside ring by use of side action. The ram comes down connecting with the arm on the outside ring forcing it to move a certain amount radially. This in turn transfers the movement to the rollers which is the second part of the device. The rollers push the punches into the piece and the action is complete. The vertical movement of the ram does not come directly in contact with the main die resulting in any cocking of the outside ring.
In the Musser et al U.S. Pat. No. 2,630,862, the basic idea and differences are as follows: This device uses dual indexing to achieve the number of holes and spacing of these holes. This operation is much the same as a single perf. The amount makes no difference as the location does not change by movement of the part itself. The staggered effect becomes evident.
In the Patrick U.S. Pat. No. 2,875,829, the basic idea and differences are as follows: This patent is capable of making two hits in one stroke of the press in the same manner of the single hit slide cam with the action of the second bit occurring only after the first cutter is retracted but there are no mechanisms for making vertically spaced slots or holes in the workpiece.
In the Robinson U.S. Pat. No. 3,374,697, the basic idea and differences are as follows: This device is for severing a tubular member and forming a tube blank with different contours at each end. This is accomplished by shearing or punching out arcuate segments of the tubular member. The tool itself uses hydraulic pistons to activate the punches.
In the Merchant U.S. Pat. No. 3,485,124, the basic idea and differences are as follows: This device pierces the cup using the basic slide cam theory. A stationary pin is put through the punch holder. A slot is put in the movable part at whatever angle is desired. When the ram pushes down the punch slides over on the pin. As the ram travels up the punch is pulled away by the same action. The slide cam is used to activate the punches and there is no capability to simultaneously form vertically spaced holes or slots.
In the Kirchner U.S. Pat. No. 3,557,649, the basic idea and differences are as follows: This device is used for the location purpose of centering the piece part so that the opening can be pierced exactly in the right location according to the part. The piercing assembly is a hydraulic unit. One of the basic differences between this apparatus and the improvement here disclosed concerns the development of a new and improved device for the simultaneous formation of vertically spaced slots and/or holes which can be either vertically aligned or which can be vertically offset relative to one another.
In the Reider U.S. Pat. No. 3,579,767, the basic idea and differences are as follows: This device is for forming flash holes in cartridge shells. The basic slide cam is used to activate the punches to form the holes but there is no provision for the forming of vertically spaced holes and/or slots in vertical alignment or in offset alignment in the workpiece.
In the Powell U.S. Pat. No. 3,580,122, the basic idea and differences are as follows: This device is used for making knockouts in sheet plastic. The idea is to hold the box itself so that the punches (112, 114) can enter from the side to make the knockout. The means of moving the punch is the slide cam where the drive is mounted on the bottom and is activated when the ram descends down and there is no provision for the formation of vertically spaced holes or slots in-line or off-line as required.
In the Fuchs U.S. Pat. No. 3,756,108, the basic idea and differences are as follows: This device is used for cutting the circumference of tubing without leaving flashes on them. The apparatus here used activates side punches with fluid pressure and the apparatus appears unrelated to the improvements herein disclosed.
In the Jannetty U.S. Pat. No. 3,782,231, the basic idea and differences are as follows: This piercing assembly has an unusual drive for activating the pin or punch by using two arms that are controlled by a rotating crank shaft that operates to pull one arm down at a time. This operation of the crank shaft causes the fixed part of the assembly to pivot in the center thus generating side movement of the slide member to contact the part to be punched for punching.
In the Kappan U.S. Pat. No. 3,949,632, the basic idea and differences are as follows: The patent discloses a tube cut-off machine which is activated by a cam 18 for cropping off the tube. The patent does not show the improvements in a punching apparatus as herein disclosed.
In the Long, et al U.S. Pat. No. 4,269,094, the basic idea and differences are as follows: The patent discloses a device for punching holes in tubes where punches are employed for punching a single hole or a set of holes at one time. By the use of gears and ratchets, the part is then indexed. Another set of holes can then be punched. The punching apparatus has nothing to do with the improvements here disclosed.